I’m afraid that child categories can only be ordered alphabetical. You can order them by placing numbers in front of them if you want. The problem is that WordPress doesn’t offer any solution to reorder child categories, which is a shame really.

Regarding the one-column menucard, I’ll leave you a reply in this topic you also posted in: https://support.redfactory.nl/forums/topic/menucard-only-in-one-column/

Cheers 🙂